Activatable material for sealing, baffling or reinforcing and method of forming same

FIELD OF THE INVENTION

0001The present invention relates generally to an activatable material, a method of forming the activatable material and a method of using the activatable material for sealing, baffling or reinforcing of components of articles of manufacture such as automotive vehicles.

BACKGROUND OF THE INVENTION

0002For many years industry, and particularly the transportation industry has been concerned with sealing, baffling, acoustic attenuation and reinforcement of articles of manufacture such as automotive vehicles. In turn, industry has developed a wide variety of materials for providing such sealing, baffling and reinforcement. The present invention, therefore, seeks to provide an improved material for sealing, baffling or reinforcement, a method of forming the improved material and a method for use of the improved material for reinforcing, sealing or baffling.

SUMMARY OF THE INVENTION

0003Accordingly, the present invention provides an activatable material and a method of sealing, baffling or reinforcing a portion of an article of manufacture such as an automotive vehicle with the activatable material. The activatable material typically includes an epoxy resin, a thermoplastic polyether and a curing agent. The activatable material may be applied to a surface of a carrier member, a surface of a component of the article of manufacture or any other substrate. According to one preferred embodiment the activatable material is inserted into a cavity of an automotive vehicle, although it is contemplated that the activatable material may be applied to any location of the vehicle. In such an embodiment, the activatable material may be applied to the carrier member prior to insertion into the cavity, although certainly not required. After application, the activatable material is preferably activated to bond the activatable material to surfaces of any substrate to which it has been applied.

0004According to one highly preferred embodiment, the activatable material is formed into a powder and applied to an adhesive material to form a synthetic material with a tacky surface and a non-tacky surface. Thereafter, the non-tacky surface may be contacted so as to bring the tacky surface into contact with a component of an article of manufacture.

BRIEF DESCRIPTION OF THE DRAWINGS

0005<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view of a reinforcement member formed in accordance with an aspect of the present invention.

0006<figref idref="DRAWINGS">FIG. 2</figref> is a perspective view of an automotive vehicle according to an aspect of the present invention.

0007<figref idref="DRAWINGS">FIG. 3</figref> is a perspective view of a panel being reinforced in accordance with an aspect of the present invention.

0008<figref idref="DRAWINGS">FIG. 4</figref> is a perspective view of a reinforced panel formed in accordance with an aspect of the present invention.

0009<figref idref="DRAWINGS">FIGS. 5–7</figref> illustrate members being adhered together according to an aspect of the present invention.

0010<figref idref="DRAWINGS">FIG. 8</figref> is a sectional view of a synthetic material formed in accordance with an aspect of the present invention.

0011<figref idref="DRAWINGS">FIG. 9</figref> is a schematic view of a synthetic material being formed in accordance with an aspect of the present invention.

DETAILED DESCRIPTION

0012The present invention is predicated upon an improved activatable material, and articles incorporating the same. The activatable material preferably assists in providing structural reinforcement, adhesion, sealing, acoustical damping properties or a combination thereof within a cavity of or upon a surface of a structure, or to one or more structural members (e.g., a body panel or structural member) of an article of manufacture (e.g., an automotive vehicle). As used herein, the phrase activatable material includes any material may be activated to change states by an ambient condition or another condition. For example, the material may expand, flow, melt, cure, a combination thereof or the like upon exposure to a condition such a heat, pressure, chemical exposure, combinations thereof or the like.

0013The activatable material typically includes an epoxy resin and a thermoplastic polyether, and optionally, one or a combination of a blowing agent, a curing agent or a filler. The activatable material preferably includes at least three of the following: <ul id="ul0001" list-style="none"><li id="ul0001-0001" num="0000"><ul id="ul0002" list-style="none"><li id="ul0002-0001" num="0014">(a) up to about 80 parts by weight of an epoxy resin;</li><li id="ul0002-0002" num="0015">(b) up to about 70 parts by weight of a thermoplastic polyether;</li><li id="ul0002-0003" num="0016">(c) up to about 5 parts by weight of a blowing agent;</li><li id="ul0002-0004" num="0017">(d) up to about 7 parts by weight of a curing agent; and</li><li id="ul0002-0005" num="0018">(e) a filler. <br /> The concentration may be higher or lower depending upon the intended application of the activatable material. In a preferred aspect of the invention, the amount by weight epoxy resin to thermoplastic polyether is from about 1:10 to about 10:1, more preferably about 1:5 to about 5:1 and still more preferably about 1:3 to about 3:1. </li></ul></li></ul>

0019The activatable material of the present invention may be applied to various articles of manufacture for adding structural integrity to portions or members of articles, for providing acoustical damping to the articles or for sealing the articles. Examples of such articles of manufacture include, without limitation, household or industrial appliances, furniture, storage containers, buildings, structures or the like. In preferred embodiments, the activatable material is applied to portions of an automotive vehicle such as body or frame members (e.g., a vehicle frame rail) of the automotive vehicle. One method of the present invention contemplates applying the activatable material to a surface of one of the above structures in an unexpanded or partially expanded state and activating the material for expanding it to a volume greater than its volume in the unexpanded state (e.g., at least 50% greater, at least 100% greater, at least 500% greater, at least 1000% greater, at least 2000% greater, at least 5000% greater or higher).

0020Percentages herein refer to weight percent, unless otherwise indicated.

0000Epoxy Resin

0021Epoxy resin is used herein to mean any of the conventional dimeric, oligomeric or polymeric epoxy materials containing at least one epoxy functional group. The polymer-based materials may be epoxy-containing materials having one or more oxirane rings polymerizable by a ring opening reaction. In preferred embodiments, the activatable material includes up to about 80% or more of an epoxy resin. More preferably, the expandable includes between about 10% and 70% by weight epoxy resin and still more preferably between about 40% and 60% by weight epoxy resin. Of course, amounts of epoxy resin may be greater or lower depending upon the intended application of the activatable material. As an example, it is contemplated that weight percentages may be lower (e.g., between about 5% and about 30%) when other ingredients such as the thermoplastic polyether, a filler, alternative polymers, combinations thereof or the like are used in greater weight percentages (e.g., between about 30% and about 80%).

0022The epoxy may be aliphatic, cycloaliphatic, aromatic or the like. The epoxy may be supplied as a solid (e.g., as pellets, chunks, pieces or the like) or a liquid (e.g., an epoxy resin). The epoxy may include an ethylene copolymer or terpolymer that may possess an alpha-olefin. As a copolymer or terpolymer, the polymer is composed of two or three different monomers, i.e., small molecules with high chemical reactivity that are capable of linking up with similar molecules. Preferably, an epoxy resin is added to the activatable material to increase the adhesion and flow properties of the material. One exemplary epoxy resin may be a phenolic resin, which may be a novalac type or other type resin. Other preferred epoxy containing materials may include a bisphenol-A epichlorohydrin ether polymer, or a bisphenol-A epoxy resin which may be modified with butadiene or another polymeric additive. Moreover, various mixtures of several different epoxy resins may be employed as well.

0000Thermoplastic Polyether

0023The activatable material typically includes one or more thermoplastic polyethers. When included, the one or more thermoplastic polyethers preferably comprise between about 1% and about 90% by weight of the activatable material, more preferably between about 3% and about 60% by weight of the activatable material and even more preferably between about 5% and about 25% by weight of the activatable material. As with the other materials, however, more or less thermoplastic polyether may be employed depending upon the intended use of the activatable material.

0024The thermoplastic polyethers typically include pendant hydroxyl moieties. The thermoplastic polyethers may also include aromatic ether/amine repeating units in their backbones. The thermoplastic polyethers of the present invention preferably have a melt index between about 5 and about 100, more preferably between about 25 and about 75 and even more preferably between about 40 and about 60 grams per 10 minutes under load of 2.16 Kg at a temperature of about 190° C. Of course, the thermoplastic polyethers may have higher or lower melt indices depending upon their intended application. Preferred thermoplastic polyethers include, without limitation, polyetheramines, poly(amino ethers), copolymers of monoethanolamine and diglycidyl ether, combinations thereof or the like.

0025Preferably, the thermoplastic polyethers are formed by reacting an amine with an average functionality of 2 or less (e.g., a difunctional amine) with a glycidyl ether (e.g., a diglycidyl ether). As used herein, the term difunctional amine refers to an amine with an average of two reactive groups (e.g., reactive hydrogens).

0026According to one embodiment, the thermoplastic polyether is formed by reacting a primary amine, a bis(secondary) diamine, a cyclic diamine, a combination thereof or the like (e.g., monoethanolamine) with a diglycidyl ether or by reacting an amine with an epoxy-functionalized poly(alkylene oxide) to form a poly(amino ether). According to another embodiment, the thermoplastic polyether is prepared by reacting a difunctional amine with a diglycidyl ether or diepoxy-functionalized poly(alkylene oxide) under conditions sufficient to cause the amine moieties to react with the epoxy moieties to form a polymer backbone having amine linkages, ether linkages and pendant hydroxyl moieties. Optionally, the polymer may be treated with a monofunctional nucleophile which may or may not be a primary or secondary amine.

0027Additionally, it is contemplated that amines (e.g., cyclic amines) with one reactive group (e.g., one reactive hydrogen) may be employed for forming the thermoplastic polyether. Advantageously, such amines may assist in controlling the molecular weight of the thermoplastic ether formed.

0028Examples of preferred thermoplastic polyethers and their methods of formation are disclosed in U.S. Pat. Nos. 5,275,853; 5,464924 and 5,962,093, which are incorporated herein by reference for all purposes. Particularly preferred thermoplastic polyethers are sold under the tradename BLOX® and is commercially available from the Dow Chemical Corporation, Midland, Mich. Advantageously, the thermoplastic polyethers can provide the activatable material with various desirable characteristics such as desirable physical and chemical properties for a wide variety of applications as is further described herein.

0000Blowing Agent

0029One or more blowing agents may be added to the activatable material for producing inert gasses that form, as desired, an open and/or closed cellular structure within the activatable material. In this manner, it may be possible to lower the density of articles fabricated from the material. In addition, the material expansion helps to improve sealing capability, acoustic damping or both.

0030The blowing agent may include one or more nitrogen containing groups such as amides, amines and the like. Examples of suitable blowing agents include azodicarbonamide, dinitrosopentamethylenetetramine, azodicarbonamide, dinitrosopentamethylenetetramine, 4,4_i-oxy-bis-(benzenesulphonylhydrazide), trihydrazinotriazine and N,N_i-dimethyl-N,N_i-dinitrosoterephthalamide.

0031An accelerator for the blowing agents may also be provided in the activatable material. Various accelerators may be used to increase the rate at which the blowing agents form inert gasses. One preferred blowing agent accelerator is a metal salt, or is an oxide, e.g. a metal oxide, such as zinc oxide. Other preferred accelerators include modified and unmodified thiazoles or imidazoles.

0032Amounts of blowing agents and blowing agent accelerators can vary widely within the activatable material depending upon the type of cellular structure desired, the desired amount of expansion of the activatable material, the desired rate of expansion and the like. Exemplary ranges for the amounts of blowing agents and blowing agent accelerators in the activatable material range from about 0% by weight to about 5% by weight and are preferably in the activatable material in fractions of weight percentages.

0033In one embodiment, the present invention contemplates the omission of a blowing agent. Preferably, however, the material, the blowing agent or both of the present invention are thermally activated. Alternatively, other agents may be employed for realizing activation by other means, such as moisture, radiation, or otherwise.

0000Curing Agent

0034One or more curing agents and/or curing agent accelerators may be added to the activatable material. Amounts of curing agents and curing agent accelerators can, like the blowing agents, vary widely within the activatable material depending upon the type of cellular structure desired, the desired amount of expansion of the activatable material, the desired rate of expansion, the desired structural properties of the activatable material and the like. Exemplary ranges for the curing agents or curing agent accelerators present in the activatable material range from about 0% by weight to about 7% by weight.

0035Preferably, the curing agents assist the activatable material in curing by crosslinking of the polymers, epoxy resins or both. It is also preferable for the curing agents to assist in thermosetting the activatable material. Useful classes of curing agents are materials selected from aliphatic or aromatic amines or their respective adducts, amidoamines, polyamides, cycloaliphatic amines, anhydrides, polycarboxylic polyesters, isocyanates, phenol-based resins (e.g., phenol or cresol novolak resins, copolymers such as those of phenol terpene, polyvinyl phenol, or bisphenol-A formaldehyde copolymers, bishydroxyphenyl alkanes or the like), or mixtures thereof. Particular preferred curing agents include modified and unmodified polyamines or polyamides such as triethylenetetramine, diethylenetriamine tetraethylenepentamine, cyanoguanidine, dicyandiamides and the like. An accelerator for the curing agents (e.g., a modified or unmodified urea such as methylene diphenyl bis urea, an imidazole or a combination thereof) may also be provided for preparing the activatable material.

0036Though longer curing times are also possible, curing times of less than 5 minutes, and even less than 30 seconds are possible for the formulation of the present invention.

0000Filler

0037The activatable material may also include one or more fillers, including but not limited to particulated materials (e.g., powder), beads, microspheres, or the like. Preferably the filler includes a relatively low-density material that is generally non-reactive with the other components present in the activatable material. While the fillers may generally be present within the activatable material to take up space at a relatively low weight, it is contemplated that the fillers may also impart properties such as strength and impact resistance to the activatable material.

0038Examples of fillers include silica, diatomaceous earth, glass, clay (e.g., including nanoclay), talc, pigments, colorants, glass beads or bubbles, glass, carbon or ceramic fibers, nylon or polyamide fibers (e.g., Kevlar), antioxidants, and the like. Such fillers, particularly clays, can assist the activatable material in leveling itself during flow of the material. The clays that may be used as fillers may include clays from the kaolinite, illite, chloritem, smecitite or sepiolite groups, which may be calcined. Examples of suitable fillers include, without limitation, talc, vermiculite, pyrophyllite, sauconite, saponite, nontronite, montmorillonite or mixtures thereof. The clays may also include minor amounts of other ingredients such as carbonates, feldspars, micas and quartz. The fillers may also include ammonium chlorides such as dimethyl ammonium chloride and dimethyl benzyl ammonium chloride. Titanium dioxide might also be employed.

0039In one preferred embodiment, one or more mineral or stone type fillers such as calcium carbonate, sodium carbonate or the like may be used as fillers. In another preferred embodiment, silicate minerals such as mica may be used as fillers.

0040When employed, the fillers in the activatable material can range from 10% to 90% by weight of the activatable material. According to some embodiments, the activatable material may include from about 0% to about 3% by weight, and more preferably slightly less that 1% by weight clays or similar fillers. Powdered (e.g. about 0.01 to about 50, and more preferably about 1 to 25 micron mean particle diameter) mineral type filler can comprise between about 5% and 70% by weight, more preferably about 10% to about 50% by weight.

0000Other Components and Additives

0041It is contemplated that most nearly any additional chemicals, materials or otherwise may be added to the activatable material assuming they are suitable for the activatable material and suitable for a chosen application of the activatable material.

0042Additional polymers may be included in the activatable material in amounts between about 0.01% and about 80% by weight, more preferably between about 1% and about 40% by weight and even more preferably between about 3% and about 20% by weight of the activatable material. Possible polymers include, without limitation, elastomer-containing adducts, halogenated polymers, polycarbonates, polyketones, urethanes, polyesters, silanes, sulfones, allyls, olefins, styrenes, acrylates, methacrylates, epoxies, silicones, phenolics, rubbers, polyphenylene oxides, terphthalates, acetates (e.g., EVA), acrylates, methacrylates (e.g., ethylene methyl acrylates or ethylene ethyl acrylate maleic anhydride terpolymers) or mixtures thereof. Other potential polymeric materials may be or may include include, without limitation, polyethylene, polypropylene, polystyrene, polyolefin, polyacrylate, poly(ethylene oxide), poly(ethyleneimine), polyester, polyurethane, polysiloxane, polyether, polyphosphazine, polyamide, polyimide, polyisobutylene, polyacrylonitrile, poly(vinyl chloride), poly(methyl methacrylate), poly(vinyl acetate), poly(vinylidene chloride), polytetrafluoroethylene, polyisoprene, polyacrylamide, polyacrylic acid, polymethacrylate.

0043Other additives, agents or performance modifiers may also be included in the activatable material as desired, including but not limited to a UV resistant agent, a flame retardant, an impact modifier, a heat stabilizer, a colorant, a processing aid, a lubricant, a reinforcement (e.g., chopped or continuous glass, ceramic, aramid, or carbon fiber, particulates or the like).

0044When determining appropriate components for the activatable material, it may be important to form the material such that it will only activate (e.g., flow, foam or otherwise change states) at appropriate times or temperatures. For instance, in most applications, it is undesirable for the material to be reactive at room temperature or otherwise at the ambient temperature in a production environment. More typically, the activatable material becomes activated to flow at higher processing temperatures. As an example, temperatures such as those encountered in an automobile assembly plant may be appropriate, especially when the activatable material is processed along with the other components at elevated temperatures or at higher applied energy levels, e.g., during painting preparation steps. Temperatures encountered in many coating operations (e.g., in a paint curing oven), for instance, range up to about 250° C. or higher.

0000Formation and Application of the Activatable Material

0045Formation of the activatable material can be accomplished according to a variety of new or known techniques. Preferably, the activatable material is formed as a material of substantially homogeneous composition. However, it is contemplated that various combining techniques may be used to increase or decrease the concentration of certain components in certain locations of the activatable material.

0046According to one embodiment, the activatable material is formed by supplying the components of the material in solid form such as pellets, chunks and the like, in liquid form or a combination thereof. The components are typically combined in one or more containers such as large bins or other containers. Preferably, the containers can be used to intermix the components by rotating or otherwise moving the container. Thereafter, heat, pressure or a combination thereof may be applied to soften or liquidize the components such that the components can be intermixed by stirring or otherwise into a single homogenous composition.

0047According to another embodiment, the activatable material may be formed by heating one or more of the components that is generally easier to soften or liquidize such as the polymer based materials to induce those components into a mixable state. Thereafter, the remaining components may then be intermixed with the softened components.

0048Depending upon the components used, it may be important to assure that the temperature of the components remains below certain activation temperatures that might cause the activatable material to activate (e.g., form gasses, flow or otherwise activate), cure (e.g., harden, stiffen or otherwise change states) or both. Notably, when the activatable material contains a blowing agent, it is typically desirable to maintain the temperature of the activatable material below a temperature that will activate the blowing agent during formation of the activatable material or before the activatable material is applied to a surface. In situations where it is desirable to maintain the activatable material at lower temperatures it may be desirable to maintain the components in a semi-solid or viscoelastic state using pressure or a combination of pressure and heat to intermix the components of the activatable material. Various machines have been designed to applying heat, pressure or both to materials.

0049After formation of the activatable material, the material is typically applied to a surface or substrate and activated. Activation of the material may include at least some degree of foaming or bubbling in situations where the activatable material includes a blowing agent. Such foaming or bubbling can assist the activatable material in wetting a substrate and forming an intimate bond with the substrate. Alternatively, however, it shall be recognized that the activatable material may be activated to flow without foaming or bubbling and may still substantially wet the substrate to form an intimate bond. Formation of the intimate bond will typically but not necessarily occur upon curing of the activatable material.

0050It shall be understood that, depending upon its the intended application, the activatable material may be applied and activated in different ways and at different times. Thus, exemplary uses of the activatable material are discussed below to illustrate preferred methodologies of application and activation of the activatable material. In particular, the activatable material may used for, amongst others, reinforcement, sealing and adhering, acoustic baffling or the like.

0000Reinforcement

0051The activatable material may be used to reinforce structural members of an article of manufacture. When used for reinforcement, the activatable material may be employed by itself, may be employed in conjunction with other materials (e.g., a backing), may be applied to a carrier member or the like.

0052According to one embodiment, the activatable material of the present invention is applied to a carrier member to form a reinforcement member and the reinforcement member is inserted within a cavity formed by a structural member of an automotive vehicle. The structural member of the automotive vehicle may be nearly any member of the vehicle including, but not limited to, frame members, body member, pillar structures, closure panels, roof assemblies, bumpers, combinations thereof or the like.

0053The carrier member may be selected from a variety of conventional and novel configurations. The activatable material of the present invention may thus be applied to a carrier member, such as a molded, extruded or stamped member (e.g., metal or plastic, foamed or unfoamed; exemplary materials of which include aluminum, magnesium, titanium, steel, molding compound (e.g., sheet or bulk molding compound), polyamide (e.g., nylon 6 or nylon 6,6), polysulfone, thermoplastic imide, polyether imide, polyether sulfone or mixtures thereof.

0054Examples of carrier members, structural reinforcement applications or the like, which may be employed in the present invention are disclosed in U.S. Pat. Nos. 6,474,723; 6,467,834; 6,419,305; 6,358,584; 6,311,452; 6,296,298; 6,263,635, all of which are hereby incorporated by reference. Other examples are disclosed in U.S. patent application Ser. Nos. 10/236,315; 10/098,952; 10/337,446; 09/939,152; 09/459,756; 60/409,625; 60/333,273; 60/317,201 all of which are also incorporated herein by reference for all purposes.

0055For purposes of illustration, <figref idref="DRAWINGS">FIG. 1</figref> shows a reinforcement member <b>10</b> comprised of a carrier member <b>12</b> having masses <b>14</b> of activatable material disposed thereon. As shown the carrier member <b>12</b> is skeletal and includes a plurality of ribs <b>20</b>. Moreover, the activatable material has been disposed upon the carrier member <b>12</b> in layers of substantially uniform thickness. It is contemplated however, that the carrier member <b>12</b> and the activatable material may be formed according to any suitable shape or configuration depending upon their intended application.

0056The exemplary reinforcement member <b>10</b>, as shown in <figref idref="DRAWINGS">FIG. 2</figref>, has been inserted into a cavity <b>22</b> that is defined by a pillar structure <b>24</b> of an automotive vehicle <b>26</b>. After insertion into the cavity <b>22</b>, the masses <b>14</b> of activatable material are preferably activated to adhere to walls of the pillar structure <b>24</b> that define the cavity <b>22</b>. For example, the masses <b>14</b> may be exposed to elevated temperature in an e-coat or painting operation thereby causing the masses <b>14</b> of activatable material to become flowable and expand to contact the walls of the pillar structure <b>24</b>. At the same time or thereafter, the masses <b>14</b> may cure to adhere and bond to the walls of the pillar structure <b>24</b> thereby forming a reinforced structural system <b>28</b> for the vehicle <b>26</b>.

0057Also for purposes of illustration, <figref idref="DRAWINGS">FIGS. 3 and 4</figref> show the formation of a reinforced panel <b>34</b> comprised of a panel <b>36</b>, a layer <b>38</b> of activatable material and a backing material <b>42</b>. The panel <b>36</b> may be provided by any suitable component of the automotive vehicle. According preferred embodiment, the panel <b>36</b> is provided as an inner or outer body panel (e.g., a door panel, a roof panel, a side panel, a closure panel or the like) of the vehicle.

0058The backing material <b>42</b> may be chosen from a variety of materials. For example, and without limitation, the backing material may be formed of metal foils, metal sheets, metal screens or the like. As alternative examples, the backing material may be formed of polymeric (e.g., thermoplastic) films, sheets or mesh. In still other alternative embodiments, the backing material may be formed of cellulose fiber material such as impregnated or non-impregnated paper, wood or the like.

0059The reinforced panel <b>34</b> is formed by applying the layer <b>38</b> of activatable material to a surface <b>44</b> of the automotive vehicle panel <b>36</b> and applying the backing material <b>42</b> to the layer <b>38</b> of activatable material. It should be understood that the layer <b>38</b> of activatable material may be applied to the automotive vehicle panel <b>36</b> before, after or simultaneous with application of the backing material material <b>42</b> to the layer <b>38</b>.

0060After application, the layer <b>38</b> of activatable material is preferably activated to adhere and bond to the panel <b>36</b> and the backing material <b>42</b>. For example, the layer <b>42</b> may be exposed to elevated temperature in an e-coat or painting operation thereby causing the layer <b>42</b> of activatable material to become flowable and expand to contact and wet the panel <b>36</b> and the backing material <b>42</b>. At the same time or thereafter, the layer <b>42</b> may cure to adhere to the panel <b>36</b> and the backing material <b>42</b> thereby forming the reinforced panel <b>34</b>.

0061One exemplary activatable material that is particularly suitable for use in reinforcement application is in table I below.

0062<tables id="TABLE-US-00001" num="00001"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="2"><colspec colname="1" colwidth="154pt" align="left" /><colspec colname="2" colwidth="63pt" align="center" /><thead><row><entry namest="1" nameend="2" rowsep="1">TABLE I</entry></row><row><entry namest="1" nameend="2" align="center" rowsep="1" /></row><row><entry /><entry>Percent of Formula</entry></row><row><entry>Ingredient</entry><entry>Wt. %</entry></row><row><entry namest="1" nameend="2" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="2"><colspec colname="1" colwidth="154pt" align="left" /><colspec colname="2" colwidth="63pt" align="char" char="." /><tbody valign="top"><row><entry>Thermoplastic Polyether</entry><entry>4.57</entry></row><row><entry>2-Propenoic acid, 2-methyl-, oxiranylmethyl ester,</entry><entry>0.31</entry></row><row><entry>polymer with ethane and methyl 2-propenoate</entry></row><row><entry>Polymer of Epoxy Resin &amp; Bisphenol A</entry><entry>12.79</entry></row><row><entry>P-Aramide Fiber</entry><entry>2.74</entry></row><row><entry>Ethylene Methyl Acrylate Copolymer</entry><entry>3.47</entry></row><row><entry>2-Propenenitrile, polymer with 1,3-butadiene,</entry><entry>38.55</entry></row><row><entry>carboxy-terminated, polymer with bisphenol A</entry></row><row><entry>diglycidyl ether homopolymer and epichlorohydrin-</entry></row><row><entry>formaldehyde-phenol polymer</entry></row><row><entry>Polymer of Epoxy Resin &amp; Bisphenol A</entry><entry>18.31</entry></row><row><entry>Reaction Product of Epichlorolhydrin Bisphenol A</entry><entry>6.27</entry></row><row><entry>Epoxy Phenol Novolac Resin</entry><entry>2.89</entry></row><row><entry>Epoxy Flexibilizer</entry><entry>2.55</entry></row><row><entry>Azodicarbonamide (90%) &amp; Benzenesulfinic Acid,</entry><entry>0.71</entry></row><row><entry>Zinc Salt (10%)</entry></row><row><entry>Azodicarbonamide</entry><entry>1.38</entry></row><row><entry>Modified Urea</entry><entry>0.37</entry></row><row><entry>Nanoclay</entry><entry>1.34</entry></row><row><entry>Cyanoguanidine</entry><entry>3.41</entry></row><row><entry>Pigment</entry><entry>0.34</entry></row><row><entry namest="1" nameend="2" align="center" rowsep="1" /></row></tbody></tgroup></table></tables><br /> While table I provides one specific formulation, it is contemplated that weight percentages of the various components may be varied by +/−20%, by +/−50% or more. Moreover, components may be removed or added and components may be replaced. For example, it may be desirable to omit one or more of the modified urea, nanoclay, cyanoguanidine, pigment or other ingredients. Further, other blowing agent may be substituted as may other methacrylates, epoxies, fillers, fibers or otherwise. <br /> Structural Adhesive

0063According to another embodiment, it is contemplated that an activatable material according to the present invention may be employed as a structural adhesive material. In such an embodiment, the material is typically activated and cured (e.g., at temperatures common to e-coat or automotive painting operatings) to adhere to a first member and a second member. Contact with attachment surface of the first member and the second member may occur prior to or during activation and curing of the material. Examples of structural adhesive applications are disclosed in U.S. patent application Ser. Nos. 10/234,902; 10/386,287; 60/451,811, all of which are incorporated herein by reference for all purposes.

0064Referring to <figref idref="DRAWINGS">FIG. 5–7</figref>, there is illustrated a first member <b>50</b> and a second member <b>52</b> that come together to form a joint <b>54</b> (e.g. a hem flange joint) hem flange. As shown the first member <b>50</b> has an end portion <b>58</b> that forms a cavity <b>60</b> for receiving a free end <b>64</b> of the second member <b>52</b>, which may be positioned as desired within the cavity <b>60</b>. An activatable material <b>68</b> according to the present invention is also positioned within the cavity <b>60</b> such that upon activation and curing of the material <b>68</b>, the first member <b>50</b> is adhered to the second member <b>52</b>. Of course, it is contemplated that the activatable material of the present invention may be employed to structurally adhere any members together. Examples of suitable materials and applications, which may benefit from the activatable material of the present invention are included in U.S. Pat. No. 5,985,435, which is incorporated herein for all purposes.

0065One exemplary activatable material that is particularly suitable for use as a structural adhesive is in table II below.

0066<tables id="TABLE-US-00002" num="00002"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="offset" colwidth="21pt" align="left" /><colspec colname="1" colwidth="119pt" align="left" /><colspec colname="2" colwidth="77pt" align="center" /><thead><row><entry /><entry namest="offset" nameend="2" rowsep="1">TABLE II</entry></row><row><entry /><entry namest="offset" nameend="2" align="center" rowsep="1" /></row><row><entry /><entry>Ingredient</entry><entry>Weight %</entry></row><row><entry /><entry namest="offset" nameend="2" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="offset" colwidth="21pt" align="left" /><colspec colname="1" colwidth="119pt" align="left" /><colspec colname="2" colwidth="77pt" align="char" char="." /><tbody valign="top"><row><entry /><entry>Ethylene Methyl Acrylate Copolymer</entry><entry>53.69</entry></row><row><entry /><entry>Thermoplastic Polyether</entry><entry>9.76</entry></row><row><entry /><entry>Polymer of Epoxy Resin and Bisphenol</entry><entry>34.17</entry></row><row><entry /><entry>Cyanoguanidine or Dicyandiamide</entry><entry>1.95</entry></row><row><entry /><entry>Blowing agent</entry><entry>0.23</entry></row><row><entry /><entry>Pigment</entry><entry>0.20</entry></row><row><entry /><entry namest="offset" nameend="2" align="center" rowsep="1" /></row></tbody></tgroup></table></tables><br /> While table II provides one specific formulation, it is contemplated that weight percentages of the various components may be varied by +/−20%, by +/−50% or more. Moreover, components may be removed or added and component may be replaced. <br /> Non-Tacky Surface

0067In another embodiment of the present invention, an outer surface of the material of the present invention is treated for allowing it to be handled without undesirable material transfer or tackiness. Thus, it is possible that a synthetic material may be provided with a layer (from less than about 10 microns to about 2 cm (e.g., on the order of less than about 1 mm)) that is generally free of tack for facilitating handling. This layer may take the form of a plastic transfer film, a water based coating, a powder coating or otherwise. The present invention thus also contemplates a tacky structural adhesive material having a layer providing handling surface that is generally free of tack to the touch. It is also contemplated that the structural adhesive material, the layer or both may be formed of the activatable material of the present invention.

0068Referring to <figref idref="DRAWINGS">FIG. 8</figref>, there is illustrated a synthetic material <b>78</b> having a layer <b>80</b> of structural adhesive material having a layer <b>82</b> of substantially tack-free material (i.e., tack-free at room temperature of about 20° C.) disposed thereon. As shown in <figref idref="DRAWINGS">FIG. 9</figref>, the layer <b>82</b> of substantially tack-free material is forced by applying a powder <b>86</b> or other particulated form that is pressed (e.g., rolled via a roller) into intimate contact with the layer <b>80</b> of adhesive material.

0069Layers of substantially tack-free material and layers of tacky material, which could benefit from the use of the activatable material of the present invention are disclosed in copending applications Ser. Nos. 10/217,991; 60/415,511, which are incorporated herein for all purposes. Moreover, it is contemplated that the layers of substantially tack-free material and the layers of structural adhesive material may include correspondence components as described in the aforementioned application.

0070Advantageously, the layer <b>82</b> of substantially tack-free material provides a substantially tack-free surface <b>88</b>, which may be contacted by an individual, with a machine or otherwise such that a tacky surface <b>90</b> of the adhesive material may be contacted with a surface of a carrier member, a member of an article of manufacture (e.g., an automotive vehicle) or the like. As shown in <figref idref="DRAWINGS">FIGS. 8 and 9</figref>, the tacky surface <b>90</b> may be temporarily covered with a protective layer <b>94</b> (e.g., release tape) until application of the material to a surface.

0071One exemplary activatable material that is particularly suitable for use in structural powder applications is in table III below.

0072<tables id="TABLE-US-00003" num="00003"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="offset" colwidth="28pt" align="left" /><colspec colname="1" colwidth="119pt" align="left" /><colspec colname="2" colwidth="70pt" align="center" /><thead><row><entry /><entry namest="offset" nameend="2" rowsep="1">TABLE III</entry></row><row><entry /><entry namest="offset" nameend="2" align="center" rowsep="1" /></row><row><entry /><entry>Ingredient</entry><entry>Wt. %</entry></row><row><entry /><entry namest="offset" nameend="2" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="offset" colwidth="28pt" align="left" /><colspec colname="1" colwidth="119pt" align="left" /><colspec colname="2" colwidth="70pt" align="char" char="." /><tbody valign="top"><row><entry /><entry>Solid Epoxy Resin</entry><entry>20.53</entry></row><row><entry /><entry>Thermoplastic Polyether</entry><entry>11.17</entry></row><row><entry /><entry>Epoxy/Elastomer Adduct</entry><entry>11.91</entry></row><row><entry /><entry>Nanoclay</entry><entry>1.79</entry></row><row><entry /><entry>Solid Epoxy Resin in Diglycidyl Ether</entry><entry>45.39</entry></row><row><entry /><entry>Dicyandiamide</entry><entry>9.13</entry></row><row><entry /><entry>Pigment</entry><entry>0.08</entry></row><row><entry /><entry namest="offset" nameend="2" align="center" rowsep="1" /></row></tbody></tgroup></table></tables><br /> While table I provides one specific formulation, it is contemplated that weight percentages of the various components may be varied by +/−20%, by +/−50% or more. Moreover, components may be removed or added and component may be replaced. <br /> Extrusion

0073Regardless of the particular use, it has been found that activatable materials according to the present invention are particularly suitable for processing and/or application via extrusion. According to one preferred embodiment of the present invention, various components may be premixed into one, two or more pre-mixtures and introduced at one or various locations in a single or twin-screw extruder. Thereafter, the heat and pressure provided by the extruder mixes the activatable material into a single generally homogeneous composition, and preferably does so without activating the material. The material of the present invention may be applied, by extrusion, to any suitable surface of a carrier, a member of an article of manufacture (e.g., an automotive vehicle) or the like. In one embodiment, an automated or robotic extrusion applicator (e.g., a mini-applicator) is employed. Examples of these types of application and applicators are disclosed in U.S. Pat. No. 5,358,397 and U.S. patent application Ser. No. 10/342,025 both of which are hereby incorporated by reference for all purposes.

0074One exemplary activatable material that is particularly suitable for use in extrusion techniques is in table IV below.

0075<tables id="TABLE-US-00004" num="00004"><table frame="none" colsep="0" rowsep="0"><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="offset" colwidth="21pt" align="left" /><colspec colname="1" colwidth="126pt" align="left" /><colspec colname="2" colwidth="70pt" align="center" /><thead><row><entry /><entry namest="offset" nameend="2" rowsep="1">TABLE IV</entry></row><row><entry /><entry namest="offset" nameend="2" align="center" rowsep="1" /></row><row><entry /><entry>Ingredient name:</entry><entry>Wt. %</entry></row><row><entry /><entry namest="offset" nameend="2" align="center" rowsep="1" /></row></thead><tbody valign="top"><row><entry /></row></tbody></tgroup><tgroup align="left" colsep="0" rowsep="0" cols="3"><colspec colname="offset" colwidth="21pt" align="left" /><colspec colname="1" colwidth="126pt" align="left" /><colspec colname="2" colwidth="70pt" align="char" char="." /><tbody valign="top"><row><entry /><entry>Solid Epoxy Resin</entry><entry>36.08</entry></row><row><entry /><entry>Nanoclay</entry><entry>1.96</entry></row><row><entry /><entry>Terpolymer of Ethylene, Methyl Acrylate</entry><entry>26.24</entry></row><row><entry /><entry>Monomer and Glycidyl Methacrylate</entry></row><row><entry /><entry>Thermoplastic Polyether</entry><entry>3.28</entry></row><row><entry /><entry>Flexibilizer</entry><entry>6.56</entry></row><row><entry /><entry>Liquid Epoxy Resin</entry><entry>3.28</entry></row><row><entry /><entry>Epoxy Phenol Novalac Resin</entry><entry>4.92</entry></row><row><entry /><entry>Dicyandiamide</entry><entry>3.28</entry></row><row><entry /><entry>Modified Urea</entry><entry>1.32</entry></row><row><entry /><entry>Activated Azodicarbonamide</entry><entry>2.29</entry></row><row><entry /><entry>Pigments</entry><entry>0.30</entry></row><row><entry /><entry>Aramid Fiber</entry><entry>1.96</entry></row><row><entry /><entry>Epoxy/Elastomer Adduct</entry><entry>8.53</entry></row><row><entry /><entry namest="offset" nameend="2" align="center" rowsep="1" /></row></tbody></tgroup></table></tables><br /> While table IV provides one specific formulation, it is contemplated that weight percentages of the various components may be varied by +/−20%, by +/−50% or more. Moreover, components may be removed or added and components may be replaced.

0076According to another preferred application, the activatable material of the present invention can be formed as masses (e.g., strands, strips or the like), which can be packaged together in contact with each other or separated (e.g., by release tape). According to such embodiment, the masses are preferably separable from each other without experiencing any substantially cohesive failure from bonding with adjacent masses. Thus, the masses may be peeled away from one another and applied to a substrate (e.g., a carrier, a member or otherwise) in manners described herein. Preferably such activatable material can be heated to expand and cure as described herein as well, although not necessarily required.

0077Advantageously, the activatable material of the present invention has shown valuable properties in its applications. In particular, it has been found that the addition of various amount of thermoplastic polyethers as described herein can produce activatable materials that have relatively good adhesive properties upon curing. Moreover, activatable materials according to the present invention can exhibit relatively high strength moduli while also exhibiting relatively high strain to failure ratios.

0078Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. Plural structural components can be provided by a single integrated structure. Alternatively, a single integrated structure might be divided into separate plural components. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention.

0079The preferred embodiment of the present invention has been disclosed. A person of ordinary skill in the art would realize however, that certain modifications would come within the teachings of this invention. Therefore, the following claims should be studied to determine the true scope and content of the invention.